In these cases it is advisable to have a look in the SPAM folder of the respective email provider.
One-Time-Download Link
Most browsers are set by default so that files are automatically saved to a predefined folder during a download. If you want the selection window to open when downloading, this must be set in the browser.
Technical problems
After a release of a new version of Dasyhub, it can happen that CSRF security mechanisms cause the login to not work. You should delete the cookie of the Dasyhub page via the Browser settings.